How Much Water?
Applying sufficient irrigation at the appropriate time to produce profitable high quality vegetables while minimising nutrient leaching is the balance sought in good irrigation management of vegetable crops. Sandy soils have low water holding capacities and therefore achieving the balance is critical to not only the produce quality but to the health of the aquifer.
Once you know the operating efficiency of your irrigation system, you can use daily evaporation to work out how much water to apply to your crop. The amount of water that a crop uses can be related to evaporation from open water which is either measured directly or calculated from weather station measurements of temperature, wind speed, solar radiation and relative humidity. The amount of water the crop needs is determined by evaporation and crop growth stage.